Observational astronomy is the branch of astronomy that focuses on collecting and analyzing data from celestial objects and phenomena. This field relies on telescopes and other instruments to observe stars, planets, galaxies, and other cosmic entities. By studying the light and other signals emitted by these objects, astronomers can learn about their composition, distance, and behavior. In observational astronomy, techniques such as photometry and spectroscopy are commonly used. Photometry measures the brightness of celestial objects, while spectroscopy analyzes the light spectrum to determine chemical compositions. Together, these methods help scientists understand the universe and its many mysteries.